Aljindan Reem, Bukharie Huda, Alomar Amer, Abdalhamid Baha
Department of Microbiology, College of Medicine, University of Dammam, PO Box 2208, AlKhobar, Kingdom of Saudi Arabia.
Department of Medicine, College of Medicine, University of Dammam, PO Box 2208, AlKhobar, Kingdom of Saudi Arabia.
J Med Microbiol. 2015 Apr;64(Pt 4):400-406. doi: 10.1099/jmm.0.000033. Epub 2015 Feb 5.
Carbapenem-resistant Acinetobacter baumannii is a major health problem worldwide, especially in intensive care units (ICUs). This study aimed to detect the prevalence of A. baumannii colonization of the gastrointestinal tract of patients admitted to the ICU in two hospitals in Saudi Arabia. In addition, it aimed to characterize the molecular mechanisms of carbapenem resistance in these isolates. From January to June 2014, 565 rectal swab specimens were screened for Acinetobacer strains and carbapenem resistance using CHROMagar Acinetobacter and CHROMagar KPC agar plates, respectively. Organism identification and susceptibility were detected using the Vitek 2 system. A total of 47 Acinetobacter spp. were detected, and 35 were resistant to carbapenem, making the prevalence of Acinetobacter spp. 8.3% (47/565) and carbapenem resistance (6.2%, 35/565). The 47 strains showed remarkable clonal diversity as revealed by PFGE. Using PCR, OXA-51, a chromosomal marker for A. baumannii, was detected in 46 strains. OXA-23 β-lactamase was detected in all 35 carbapenem-resistant A. baumannii. No IMP, VIM, SPM, SIM, GIM, KPC or NDM β-lactamases were detected in these isolates. Thus, OXA-23 was the main mechanism of carbapenem resistance in these isolates. To the best of our knowledge, this is the first study to detect the prevalence of Acinetobacter colonization in the digestive tract of ICU patients in Saudi Arabia. This study revealed the importance of having well-established protocols for early identification of these multidrug-resistant organisms, optimizing infection-control strategies and having active surveillance studies to reduce morbidity, mortality and cost.
耐碳青霉烯类鲍曼不动杆菌是全球主要的健康问题，在重症监护病房（ICU）尤为突出。本研究旨在检测沙特阿拉伯两家医院ICU收治患者胃肠道中鲍曼不动杆菌的定植率。此外，还旨在阐明这些分离株对碳青霉烯类耐药的分子机制。2014年1月至6月，分别使用嗜麦芽窄食单胞菌显色培养基和KPC显色培养基平板对565份直肠拭子标本进行鲍曼不动杆菌菌株及耐碳青霉烯类检测。使用Vitek 2系统进行菌种鉴定和药敏检测。共检测到47株不动杆菌属，其中35株对碳青霉烯类耐药，不动杆菌属的定植率为8.3%（47/565），耐碳青霉烯类的比例为6.2%（35/565）。脉冲场凝胶电泳（PFGE）结果显示，这47株菌株具有显著的克隆多样性。通过PCR检测，在46株菌株中检测到鲍曼不动杆菌的染色体标记物OXA-51。在所有35株耐碳青霉烯类鲍曼不动杆菌中均检测到OXA-23 β-内酰胺酶。这些分离株中未检测到IMP、VIM、SPM、SIM、GIM、KPC或NDM β-内酰胺酶。因此，OXA-23是这些分离株对碳青霉烯类耐药的主要机制。据我们所知，这是首次在沙特阿拉伯检测ICU患者消化道中不动杆菌定植率的研究。本研究揭示了制定完善方案以早期识别这些多重耐药菌、优化感染控制策略以及开展主动监测研究以降低发病率、死亡率和成本的重要性。
